New poject: 1979 CX500D

Discussion in 'Old's Cool' started by henrymartin, Sep 29, 2011.

  1. henrymartin

    henrymartin Mr. Tourguide no more.

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    Just brought home a CX500D from 1979.

    Don't really have any experience with these bikes. Actually, I don't think I ever saw one run.

    The good: Bike is complete although in boxes, has 22k miles, seat is in great shape. Bike sat inside for 13 years.

    The bad: Bike is in boxes, there is some rust, it will need new paint, need water pump rebuild, brake rebuild, one side cover is cracked.....etc, etc, etc

    The excellent: Bike was real cheap

    Anything in particular to look for in these?

    And a second question: Restore or have a go at whatever it becomes?
    #1
  2. simestd

    simestd Packet plumber

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    I've put about 5000 miles on a 82 GL500 (a cousin model of your CX500) that I picked up last February. Mine has been super reliable, gets 50 MPG and has been simple to care for.

    What to look out for? Google the cam chain tensioner. One of the biggest problem is people didn't understand how to adjust the manual ones (which yours has) and typically over torqued the restraining bolt which is easily stripped.

    There is a wealth of knowledge over on the Honda CX & GL site

    Good luck, the factory service manual is floating around the 'Net as a .pdf and is very handy to have. Hit me up if you can't find a copy.
    #2
  3. lrutt

    lrutt SILENCE.....i kill you

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    3 things i know of they were prone to.

    Check the stator carefully. They went out and are a bitch to change as they are on the back of the motor.

    Also check the cam chain and tensioner well. early ones had issues grinding cases.

    Check the cam and followers also, I've seen a few that ate themselves up.
    #3
  4. henrymartin

    henrymartin Mr. Tourguide no more.

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    Thanks. I'll be ordering Clymers or equivalent, and tearing it apart this winter. I promised my wife that this will be my "winter" project. She said that this is exactly what I said about the CB750F I bought earlier this year, and have been riding it already :lol3 I guess I can't help myself when I see a bike in need of attention.

    I'm still working on getting a 1977 GS400X Suzuki from a lady down the street. But, she thinks it is worth way too much, so I'm letting her come to some senses.

    Here is a pic of the CX. I love the shape of the motor.

    Attached Files:

    #4
  5. henrymartin

    henrymartin Mr. Tourguide no more.

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    Since I completed my CB750F Project during the summer, I started looking for a new project to occupy me during the upcoming winter. When a 1979 CX500D showed up on Craigslist near me, I could not resist.
    What draws me to this bike is the engine itself. The twin cylinders sticking to the sides create a unique focal point, and remind me of old Guzzis. It will be a fun project.
    [​IMG]



    This particular bike has been sitting in a basement for a while. The last inspection sticker on the bike is from 1998, but whether that is the last time the bike has been on the road, is unknown to me.

    The bike came as a rolling chassis with motor in the frame, and two buckets full of parts, but upon opening the valve covers, I found that things look better than I expected.
    [​IMG]

    Unable to help myself, I decided to dive right in, and start messing with different ideas.

    At first, I thought I could get away with using a pre-fab Airtech cafe cowl and seat pan, but I did not like the look of it. Thanks to a friendly shop owner who operates a local bike shop (Eddie's Vintage), and let me borrow the Airtech to see how it fits, I did not have to buy the cowl only to find out I will not be using it.
    [​IMG]

    This, however, leaves me hanging for the time being, as I will have to come up with my own design, create a mold, and start playing with fiberglass and resin. I'm hoping that I have learned something from my failed attempts at the CB 750F tailsection, and will not waste as much time and materials on this one.
    [​IMG]

    And now it's time for me to sharpen the pencil, grab a sheet of paper, and start drawing.
    #5
  6. henrymartin

    henrymartin Mr. Tourguide no more.

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    What is a man to do on a rainy Sunday?

    I don't know, but I started taking things apart. All, except two bolts, went smoothly, and the bike is no longer in one piece.

    [​IMG]

    [​IMG]
    Actually, I've been quite busy:)
    #6
  7. henrymartin

    henrymartin Mr. Tourguide no more.

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    Guys,

    So, after spending an evening in the garage, I'm torn between two choices:

    a) fix it, return to stock, sell it, and never look back

    b) fix it, customize it, keep it and contemplate getting rid of the 750F I did this summer

    The reason being, I can only have so many bikes. I have 4 in the garage right now, and there is a '77 GS400X I've been eying. Plus, money is always an issue. Doing the CX the right way (powder, seat, motor teardown, exhaust...)will cost more than what I could sell it for, whereas keeping it like it is, a little cleaning, painting, new tires, brakes rebuild, etc will leave me with a few dollars left over after I sell it.

    The CX500 has this going for me: Shaft drive, cool looking engine, rockers, ease of engine removal, ease of maintenance

    The CB750F has this going for me: Almost completely rebuilt, made by me and for me, so it fits me while riding it (position, comfort), there is no other one exactly like it.

    The GS400X is just cool project to play with down the road.

    Out of the two (CX or CB), not looking for performance, which would you keep and why?
    #7
  8. simestd

    simestd Packet plumber

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    I'd take care of the frame rust, put the CX500 back on the road and ride it a while. If it grows on you, then it's a keeper, otherwise pass it on in good shape to someone who will appreciate it.

    Mine is a super around town, 50 MPG, just get on it and go bike. Stone stock mine also seems to attract a lot of attention which is kind of funny. More than once I've been stopped with other ADVers who were on fully farkled, healthy 5 figure mounts and people walked right past to talk with me about the GL500. Lots of good stories too, "had one back in the day", "rode that bike all over...", "only transportation I had for X years...", " did my first saddlesore..."

    Cons (depending on your point of view):
    The bike doesn't have the rumble of a thumper or a big v twin, and the engine likes to rev which took me some getting used to. Mine seems happiest if I shift between 4-5K and keep it above 4K for steady state. On the highway at speed it can get a little buzzy, but some foam grips solved that for me. It also doesn't have the quirky personality that attracts some folks - you know, the ones who are constantly tinkering trying to solve some elusive trait or that need to perform some elaborate starting ritual that only they know.
    #8
  9. henrymartin

    henrymartin Mr. Tourguide no more.

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    Thanks. I know I just spent ton of time and money on the CB, but the simplicity of rockers and shaft are more and more appealing to me.

    I want to ride, not mess in the garage all the time.

    Either of those two bikes will be strictly for local riding only. No highway, no long distance. I have the 650GS for the long trips and the KLR250 for the woods. So, the bike I'll end up keeping will be strictly for pleasure rides.

    Shifting at 4-5k is not a problem. I do it on the CB, and the BMW already.

    Any more thoughts from others.

    There was a CX that sorta inspired me[​IMG]
    #9
  10. Sniper X

    Sniper X De Oppresso Liber

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    I have always liked the Cafe'd out CX bikes, and have seen a few. Is a great bike to do it with as long as you aren't looking for a really fast really well handling bike when done. They can be fast enough to have fun on. I love the way they look when the frame is a bright color and matched to the tank and seat cowl. That red one is fantastic.
    #10
  11. simestd

    simestd Packet plumber

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    They do make a nice looking cafe candidate, BUT be aware that rearsets are not trivial (some would say impossible) due to the unique transmission configuration and shifter articulation.

    Here's some CX500 related ADV fodder you might want to peruse :)

    http://www.advrider.com/forums/showthread.php?t=545807

    http://www.advrider.com/forums/showthread.php?t=553627

    http://www.advrider.com/forums/showthread.php?t=635210

    http://www.advrider.com/forums/showthread.php?t=629625

    BTW, I've found parts to be more plentiful and on average less expensive than equivalents for my same vintage XV750.
    #11
  12. henrymartin

    henrymartin Mr. Tourguide no more.

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    Yeah, but which one would I keep - the CB750F that I took the hatchet to, or the CX ? So many desires, so little understanding from my wife, and so little space in the garage. :deal
    #12
  13. south

    south Been here awhile

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    Pretty much the first project bike I undertook was my '78 CX500--along with a bunch of other stuff, I also have a '71 CB750K1 project waiting in the wings, BTW. Gave it a "sympathetic" freshening. The biggest mechanical (potential) issue with the "Twisted Twins" (so-called because the cylinder heads are oriented/"twisted" on the cylinders to angle the intake ports inwards to get the carbs out of the way of the rider's legs) is the "triple bypass": cam chain tensioner, stator, and water pump mechanical seal. All three replacement procedures require removing the engine from the frame and pulling the back cover off the engine, so the prevailing thought is if you have to do one of them, go ahead and do all three while you're in there. And ain't none of it cheap--replacement stators run $200-$250 for the early CX's (like yours and mine) since they consist of a triple winding (charging plus low and high RPM ignition circuits), and the mechanical seal from Honda runs about $50 (an $11 Yamaha Vmax seal will work on *some* of the CX's, just depends on the engine cover). The '78s had a recall for the cam chain tensioner early on which pretty much every surviving bike will have already had done; you can tell by checking for 3 punch marks shaped in a triangle just in front of the engine serial number--Honda had their mechanics so mark all bikes on which they performed the recall--again, just the first year '78s, but you never know if there's been an engine swap in the bike's past.

    Other than that, they're pretty much bulletproof. No real performance whatsoever, but they sold a ton of CX and CX variants--e.g., the "Customs", GL Silverwings, the turbo bikes--and the bikes definitely have a cult following. I think the best description for them I've heard is that the CX500 is "the Ford Escort of motorcycles".

    Before:

    Attached Files:

    #13
  14. south

    south Been here awhile

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    During:

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  15. south

    south Been here awhile

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    After:

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  16. south

    south Been here awhile

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    Oh, and if you drill the baffles (as the PO of my '78 did) or do an aftermarket exhaust, the bike will rumble nicely and the engine has a nifty, albeit muted, mechanical clatter courtesy of the pushrod valve train positioned right under your knees and not confined under the gas tank like on many bikes.

    It just so happens I got a bunch of low-mile GL500 spares--including an engine--with my $500 CX purchase, and, flash forward a number of years, and I just picked up a stripped, but titled, GL500I "roller" for $80, so now I can build that CX /GL cafe I've been hankering for. That is, in between working on the 6-8 other bike projects I have squirrelled away; fortunately, I've got a detached garage which The Girl rarely visits (and when she does, I just fire up the welder or the oxy-acytelene torch and that typically runs her off :evil), so I've had good success on keeping her largely ignorant of my project acquisitions.

    So, my advice is to keep both the CX and the CB: choose one to actively work on right now, and then disassemble the other one and hide the parts away somewhere(s) and just tell your wife you got rid of it. :wink:
    #16
  17. henrymartin

    henrymartin Mr. Tourguide no more.

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    Won't work. We share (shared) the garage (24x24, 2 doors), and then I built myself a carport for the car last year (hate shoveling snow off the car in the morning).

    The CB is pretty much done, except for some little, tiny tweaks I want to do, not have to do. (like modern exhaust instead of the Mac, maybe 4 into 2, new paint (even though this one is only a couple of months old), different mirrors.
    For those who haven't seen my CB: [​IMG]

    The CX is probably going to be brought to original appearance, fixed (brakes, water seal, tires, electrical) given a facelift (clean, lube, polish) and sold to finance something else. But I soooooo like the look of the red one. :huh
    #17
  18. henrymartin

    henrymartin Mr. Tourguide no more.

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    I finally managed to sneak out and do a little work on the CX500.

    When I bought it, it was with the understanding that the water pump seal needed to be replaced, so armed with some sockets and a new seal, I dug right in.
    [​IMG]

    Surprise, surprise, things are never as easy as they could be. First, I found out that the steel coolant pipes are rusted and pitted around the O-rings. The plan is to either look for new ones, or to solder fill the pitting and powdercoat the exterior. Not sure yet. Then, the shock of the day came when I took the water pump cover off.
    [​IMG]
    Whoever designed this with a steel (or cast) impeller, was a real ass.
    [​IMG]


    Then, after I pulled the rear cover off, I found a destroyed oil seal, and a broken cam chain tensioner.
    [​IMG]
    [​IMG]


    Other than that, things look pretty good in there.
    #18
  19. MIOB

    MIOB Long timer

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    If you pull the waterpump/impeller: Be really careful placing it back. The threads are really easy to damage. Also: if you take the back cover of the engine off, you will have to replace the seal behind the impeller. The Honda seal costs about 40 euros here, but Yamaha has used exactly the same seal costing 18 euros. don't know how pricing is over there, but it is worth looking at. They are a real paint to get out and in without doing damage.

    If you don't replace that seal, chances are pretty big it will start leaking cooling fluid into your oil.

    Can't help you on the tensioner. I have one spare somewhere, but not on an accessible location at the moment.
    #19
  20. henrymartin

    henrymartin Mr. Tourguide no more.

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    Thanks. I did find and bought an aftermarket mechanical seal a while back and it wasn't that bad $$$ wise. I do have to buy an OEM oil seal though, an oil seal for the shifter rod, and one for the final drive.

    I may as well bite the bullet and buy a complete gasket set and tore the thing into pieces.
    #20